I recently switched over to a CM1150V to avoid renting a modem. After switching, T3 errors became so common that I had no internet access. I ran new cable from the box, checked/replaced all f connectors and splitters. When I have a two-way splitter from the tap running directly to my cable modem, my 4 upstream channels were 52-53 and downstream channels are is high 8's/low 9's. SNR is consistanly around 40.
I had a tech come out on Saturday who spent the entire time talking to his wife on speaker phone, and didn't really want to answer any of my questions. I asked him about the high downstream & upstream levels, but all he said was my signals were good, my modem was bad. The green box (cab or whatever you call it) is located about 15 feet away in my front yard, which he checked and said the signal was pretty strong. I asked him about a cable box issue too, he paused me tv, and said there, its fixed, and left a few minutes later.
Today, i removed the splitter and connected directly from the tap to the cable modem. My downstream levels are really high, upstream is just under the max, and my cable modem is showing absolutely no issues (No T3 errors at all). What can I do to get both my downstream and upstream lower, since using a splitter will bump my upstream out of range (to 53)? Here's my current stats:
| Procedure |
Status |
Comment |
| Acquire Downstream Channel |
577750000 Hz |
Locked |
| Connectivity State |
OK |
Operational |
| Boot State |
OK |
Operational |
| Security |
Enabled |
BPI+ |
| IP Provisioning Mode |
Honor MDD |
honorMdd(4) |
|
|
|
| Downstream Bonded Channels |
| Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
SNR |
Correctables |
Uncorrectables |
| 1 |
Locked |
QAM256 |
13 |
577750000 Hz |
13.9 dBmV |
41.2 dB |
0 |
0 |
| 2 |
Locked |
QAM256 |
10 |
559750000 Hz |
13.6 dBmV |
41.1 dB |
0 |
0 |
| 3 |
Locked |
QAM256 |
11 |
565750000 Hz |
13.3 dBmV |
41 dB |
0 |
0 |
| 4 |
Locked |
QAM256 |
12 |
571750000 Hz |
13.3 dBmV |
40.9 dB |
0 |
0 |
| 5 |
Locked |
QAM256 |
14 |
583750000 Hz |
13.7 dBmV |
41 dB |
0 |
0 |
| 6 |
Locked |
QAM256 |
15 |
589750000 Hz |
13.4 dBmV |
40.8 dB |
0 |
0 |
| 7 |
Locked |
QAM256 |
16 |
595750000 Hz |
13.2 dBmV |
40.7 dB |
0 |
0 |
| 8 |
Locked |
QAM256 |
17 |
601750000 Hz |
13.2 dBmV |
40.6 dB |
0 |
0 |
| 9 |
Locked |
QAM256 |
18 |
607750000 Hz |
13.3 dBmV |
40.6 dB |
0 |
0 |
| 10 |
Locked |
QAM256 |
19 |
613750000 Hz |
13.1 dBmV |
40.5 dB |
0 |
0 |
| 11 |
Locked |
QAM256 |
20 |
619750000 Hz |
13.2 dBmV |
40.4 dB |
0 |
0 |
| 12 |
Locked |
QAM256 |
21 |
625750000 Hz |
13.1 dBmV |
40.3 dB |
0 |
0 |
| 13 |
Locked |
QAM256 |
22 |
631750000 Hz |
13.2 dBmV |
40.3 dB |
0 |
0 |
| 14 |
Locked |
QAM256 |
23 |
637750000 Hz |
12.8 dBmV |
40 dB |
0 |
0 |
| 15 |
Locked |
QAM256 |
24 |
643750000 Hz |
12.9 dBmV |
40 dB |
0 |
0 |
| 16 |
Locked |
QAM256 |
25 |
649750000 Hz |
13.3 dBmV |
40 dB |
0 |
0 |
| 17 |
Locked |
QAM256 |
26 |
655750000 Hz |
13.6 dBmV |
40 dB |
0 |
0 |
| 18 |
Locked |
QAM256 |
27 |
661750000 Hz |
13.4 dBmV |
40.1 dB |
0 |
0 |
| 19 |
Locked |
QAM256 |
28 |
667750000 Hz |
13.2 dBmV |
40.1 dB |
0 |
0 |
| 20 |
Locked |
QAM256 |
30 |
673750000 Hz |
13.3 dBmV |
39.7 dB |
0 |
0 |
| 21 |
Locked |
QAM256 |
31 |
679750000 Hz |
13.6 dBmV |
40.2 dB |
0 |
0 |
| 22 |
Locked |
QAM256 |
32 |
685750000 Hz |
13.8 dBmV |
40.3 dB |
0 |
0 |
| 23 |
Locked |
QAM256 |
33 |
691750000 Hz |
13.4 dBmV |
40.2 dB |
0 |
0 |
| 24 |
Locked |
QAM256 |
34 |
697750000 Hz |
13.5 dBmV |
40.3 dB |
0 |
0 |
| 25 |
Locked |
QAM256 |
35 |
703750000 Hz |
13.7 dBmV |
40.3 dB |
0 |
0 |
| 26 |
Locked |
QAM256 |
36 |
709750000 Hz |
14 dBmV |
40.3 dB |
0 |
0 |
| 27 |
Locked |
QAM256 |
37 |
715750000 Hz |
13.8 dBmV |
40.2 dB |
0 |
0 |
| 28 |
Locked |
QAM256 |
38 |
721750000 Hz |
13.9 dBmV |
40.2 dB |
0 |
0 |
| 29 |
Locked |
QAM256 |
39 |
727750000 Hz |
14 dBmV |
40.2 dB |
0 |
0 |
| 30 |
Locked |
QAM256 |
40 |
733750000 Hz |
13.7 dBmV |
40 dB |
0 |
0 |
| 31 |
Locked |
QAM256 |
41 |
739750000 Hz |
13.9 dBmV |
40 dB |
0 |
0 |
| 32 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
0.0 dB |
0 |
0 |
|
|
|
| Upstream Bonded Channels |
| Channel |
Lock Status |
US Channel Type |
Channel ID |
Symbol Rate |
Frequency |
Power |
| 1 |
Locked |
ATDMA |
5 |
5120 Ksym/sec |
36500000 Hz |
48 dBmV |
| 2 |
Locked |
ATDMA |
6 |
5120 Ksym/sec |
30100000 Hz |
48 dBmV |
| 3 |
Locked |
ATDMA |
7 |
5120 Ksym/sec |
23700000 Hz |
48 dBmV |
| 4 |
Locked |
ATDMA |
8 |
5120 Ksym/sec |
17300000 Hz |
47 dBmV |
| 5 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
| 6 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
| 7 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
| 8 |
Not Locked |
Unknown |
0 |
0 Ksym/sec |
0 Hz |
0.0 dBmV |
|
|
|
| Downstream OFDM Channels |
| Channel |
Lock
Status |
Modulation /
Profile ID |
Channel
ID |
Frequency |
Power |
SNR /
MER |
Active Subcarrier
Number Range |
Unerrored
Codewords |
Correctable
Codewords |
Uncorrectable
Codewords |
| 1 |
Locked |
0 ,1 ,2 ,3 |
29 |
780000000 Hz |
14.9 dBmV |
39.2 dB |
1108 ~ 2987 |
8694582 |
4493848 |
0 |
| 2 |
Not Locked |
0 |
0 |
0 Hz |
0 dBmV |
0.0 dB |
0 ~ 4095 |
0 |
0 |
0 |
|
|
|
| Upstream OFDMA Channels |
| Channel |
Lock Status |
Modulation / Profile ID |
Channel ID |
Frequency |
Power |
| 1 |
Not Locked |
0 |
0 |
0 Hz |
0 dBmV |
| 2 |
Not Locked |
0 |
0 |
0 Hz |
0 dBmV |
|
EG
Expert
•
108.3K Messages
5 years ago
The upstream power at 48 dB is o/k as long as it doesn't fluctuate higher. The downstream is indeed high. You could knock it down by using a forward path only attenuator. It won't affect the upstream power;
https://www.amazon.com/line-Signal-Forward-Attenuator-FPA6-54/dp/B07882H96R
If you are not actually having any connectivity problems, just leave it alone. No need to focus on the numbers.
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0
Virginia804
New Poster
•
6 Messages
5 years ago
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0
EG
Expert
•
108.3K Messages
5 years ago
O/k well that's not good. Perhaps the connection from the street is impaired. It may be best to get a tech out to investigate / correct this one !
Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.
Good luck !
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Virginia804
New Poster
•
6 Messages
5 years ago
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0
Virginia804
New Poster
•
6 Messages
5 years ago
Comcast tech came out again on Tuesday and checked the lines. My upstream level at the tap was 49, but he said that it was within Comcast's specs. I tried to get him to lower my upstream/get me in contact with someone who could, but that was a losing battle. After he left, I bought a Channel Vision C-0300 Return Path Amplifier from Amazon, which arrived today. I set it up on the longest run in my house, and my upstream levels have dropped to the low 40s/upper 30s. My CM1150V's log is empty, and my internet is back to what I'm paying for.
I'd suggest that anyone who is currently renting a Comcast modem and is planning on switching to a CM1150V check their upstream/downstream power levels in their logs before switching. The Comcast log was showing 49, but my CM1150V's upstream was b/t 50-53 on the same coax line. Once I brought it down to <46, my modem has been working flawlessly.
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EG
Expert
•
108.3K Messages
5 years ago
Glad you got it figured out ! Thread now being closed.
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0
patkiptoo
Visitor
•
1 Message
4 years ago
Remove any splitters along the line. I discovered that I had a directv splitter along my line. Removed the splitter and now have direct connection. dBmV came within range. Not sure why technician had used/left the directv 4-way splitter on my comcast internet line.
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0
EG
Expert
•
108.3K Messages
4 years ago
@user_patkiptoo
Please create a new topic of your own here on this board detailing your issue. Thanks. 8 month old dead now being closed.
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